SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be2162cbb819f15f1f55cbdaca9578414c3a376020168947b4e29945908d8903' 
  AND token = 'BmUu3U9JAwNbjPJ8zr74rgxYqPyle4DbIwpNpYijBnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}